I'm setting the stage to do some research on crystal malts, trying to identify the following:
1)How much ppg you get from different crystal malts
2)How fermentable the sugars are

I'm going to do some simple experiments with 1gal batches as follow:

1)Separated tests will be done, one with crystal 10L, one with crystal 40L and one with crystal 120L
2)The grain bill for each test/batch will be 1 pound of crystal malt + 1/4lb of rice rulls. The crystal malt will be milled or even blended to a fine powder to extract close to 100% of its potential.
3)Using this tiny 2gal cooler, I'm going to mash/steep each grain bill at 155F for 30min to extract the sugars. I'm using 155F just as reference as I don't think it will actually matter since I don't need to covert starch to sugars. Sugars on a crystal malt should be already there.
4)Will drain and sparge to collect 1gal of wort for fermentation
5)To Ferment with S04 yeast at 70F until FG is achieved
6)Will measure OG and FG and get the PPG and attenuation, calculating how much fermentable the sugars are.

The plan is to do this test multiple times, also using different yeast strains, so the numbers can narrow and I can get a smaller standard deviation.

My objective is to get a good understanding of the effects of crystal malts on the FG of a recipe.

What you guys think? Anything I should change in my process? Thoughts?Am I crazy or something?

What you guys think? Anything I should change in my process? Thoughts?Am I crazy or something?

I applaud your creativity, but I'm sure this information is out there. I mean, the PPG for the malts is certainly available, and the fermentability info should be somewhere as well (I don't know where - but gotta be somewhere on the interwebz! )

I'm wondering what would happen if you mashed 1lb 6 row with 1 lb of the various crystals for the enzymes. I may have to do your experiment, using the same setup and a 50/50 grain bill. Then test at various temperatures.

I think that this is definately going to happen when I get my new brewery built...

I'm wondering what would happen if you mashed 1lb 6 row with 1 lb of the various crystals for the enzymes. I may have to do your experiment, using the same setup and a 50/50 grain bill. Then test at various temperatures.

I think that this is definately going to happen when I get my new brewery built...

That's a good point - I'm not sure that crystal by itself is capable of converting...

EDIT - one more thought - doesn't brewing software already use the fermentabilty of crystal in the FG projection?

Again, not trying to be a debbie-downer, but just thinking that this information has to be out there already...

All very good points indeed.
I have thought about that also, as to how the diastatic power from a base malt would affect the fermentability of the crystal sugars.
So my plan include testing just the crystal malt first, then the next step will be to test a batch with 100% base malt, then the last stage to test a 50/50% basemalt/crystal. Crystal malt doesn't have any enzymes.

All brewing softwares that I'm aware of assume everything as 100% fermentable, crystal, carapils, even lactose ( I hate this). This is why I don't use then and built my own brewing tool, so I can at least assign the fermentability I want for each ingredient.
I have looked many times for "fermentability" data on the web without luck. The only thing I found that seems to give some idea of fermentability of a malt is the "Glassy" characteristics from the spec sheets, which I currently use in my calculations.
I hope I can get some conclusive results from this experiment. Be patient guys, it will take several interactions to come up with some reliable results.
Keep shooting comments please

Are you sure about that? They treat corn sugar the same as roast barley?

Make a test. Load a batch in the software with pure lactose (or corn sugar or roasted barley), nothing else, and check the FG. I'm pretty sure it will apply the standard yeast attenuation to it.
If that has changed I'll be very surprised.

Make a test. Load a batch in the software with pure lactose (or corn sugar or roasted barley), nothing else, and check the FG. I'm pretty sure it will apply the standard yeast attenuation to it.
If that has changed I'll be very surprised.